1. Field of the Invention
This invention relates generally to an apparatus for automatically locating concealed electrical conductors and more particularly to an electrical conductor locating apparatus that utilizes a pair of horizontal sensors and a variable gain amplifier in determining the depth of the conductor and an array comprising at least two angled sensors and a vertical sensor for determining the lateral position of the conductor.
2. Description of the Prior Art
Several electronic apparatuses are presently used for automatically determining the location of concealed electrical conductors. For example, U.S. Pat. No. 4,387,340, issued to Earl J. Peterman on June 7, 1983 describes an apparatus for determining the distance to a concealed conductor that utilizes a top and bottom sensor to detect the flux from an electromagnetic signal propagating on the concealed conductor. A problem with the apparatus of the '340 patent is the need for the signals from the top and bottom sensors, e.sub.t and e.sub.b, respectively, to be accurately quantified. At mid to large distances, the values for e.sub.t and e.sub.b approach one another. Slight errors in quantifying either value are exaggerated by the subtraction step utilized in calculating the distance to the conductor, thus producing significant errors in the resulting distance measurement.
U.S. Pat. No. 4,520,317, issued to Earl J. Peterman on May 28, 1985, describes an apparatus for determining the lateral direction to a concealed electrical conductor that utilizes a pair of coaxial sensors to detect the lateral displacement of the conductor from the apparatus. A problem with the coaxial configuration of the sensors is that the sensitivity of the sensors varies greatly with increasing distance of the target conductor from the locating apparatus.